The literary world loves a good punch-up, and as feuds go, this is the Rumble in the Jungle and the Thrilla in Manila all rolled into one. Just about every contender for the US heavyweight writers' crown has weighed in and the fight has turned very nasty very quickly.

The feud has brought together John Updike, Norman Mailer and John Irving to take on an uppity pretender from the South, Tom Wolfe. And the prize, as usual, is literary greatness - entry to the 20th-century pantheon alongside the likes of Hemingway and Steinbeck.

Wolfe, having worked his way through the ranks of journalism, has staked his claim in the last two decades of the millennium with two blockbuster epics. The first, Bonfire of the Vanities, took on class and race struggle between Wall Street and the Bronx. His long-awaited second tome, A Man in Full, which came out in 1998 after a 17-year pause, did the same for the South.

The public loved both books and has bought well over a million hardback copies of A Man in Full, which narrates the fall from grace of an Atlanta property developer, Charlie Croker. But is it art? And more to the point, is it that Holy Grail of US literature: "The Great American Novel"?

The concerted response to both questions has been a contemptuous "no" from Updike, Mailer and Irving, hitherto the leading lions in the literate-but-accessible category. They say they are defending literary standards, but their defence has been down and dirty.

John Irving, at 57 the dauphin of the trio, was by far the most brutal. Of Wolfe's efforts, he said: "It's like reading a bad newspaper or a bad piece in a magazine. It makes you wince." The author of The World According to Garp added that on any page of a Wolfe novel, he could "read a sentence that would make me gag".

John Updike in his New Yorker review went in for the kill. "A Man in Full," he imperiously concluded, "still amounts to entertainment, not literature, even literature in a modest aspirant form."

Norman Mailer, writing in the New York Review of Books, compared reading the weighty Wolfe novel to making love to a 300lb woman: "Once she gets on top it's all over. Fall in love or be asphyxiated."

The message has been blunt and clear: Wolfe may sell a lot of books but he belongs on the airport shelves alongside Stephen King and all those self-improvement manuals, not in the hallowed hall of the greats.

Wolfe, however, is not the sort to turn the other cheek and slink back to his keyboard. He has instead launched a one-man verbal onslaught against his detractors, flinging entrenched reputations aside with a ferocity that has scandalised even the jaded and scarred New York book world.

"It's a tantrum. It's a wonderful tantrum," he said on the same talk show that Irving used to attack him. "A Man in Full panicked [Irving] the same way it frightened John Updike and Norman. Frightened them. Panicked them."

He described Updike and Mailer as "two old piles of bones". As for the youngest of his three opponents, he points out: "Irving is a great admirer of Dickens. But what writer does he see now constantly compared to Dickens. Not John Irving, but Tom Wolfe . . . it must gnaw at him terribly."

The feud has evidently drawn blood all round, but it is still only in its early rounds. Wolfe has a score-settling essay in the pipeline, called The Three Stooges (no prizes for guessing who). It will be published later this year in a collection of short pieces, Hooking Up, which will also include a side-swipe at an old enemy: the New Yorker, which Wolfe views as the kingpin of a literary establishment which has tried for so long to keep him out in the cold.

The Wolfe-Mailer feud is by far the oldest and cattiest of the three. As far back as 1989, Mailer remarked: "In my mind, there is something silly about a man who wears a white suit all the time, especially in New York."

Wolfe brushed off the sartorial attack, simply pointing out that "the lead dog is the one they always try to bite in the ass". To which Mailer quickly responded: "It doesn't mean you're the top dog just because your ass is bleeding."

Deep below the multiple layers of bitchiness, it is possible to pick out a substantive battle over the future of American novel. The line followed by Updike, Mailer and Irving is that there is a qualitative leap from journalism to literature which Wolfe has tried but failed to complete.

Updike puts the argument most clearly in his New Yorker deconstruction of A Man in Full: "So much local information, so many well-lighted settings, so much news do not quite knit into a novel powered by the human spirit as it gropes and struggles for focus. Wolfe has perhaps too many opinions for a novelist: his characters have a hard time breaking out of the illustrative mold in which they are cast."

Wolfe does not disown his past as a hack. Instead, he claims to have transformed his former trade into something higher - New Journalism, a breathless running-commentary narrative style he pioneered in books like The Right Stuff about the early astronauts. It is a style which has left its mark on a generation of magazine writers.

Now Wolfe is arguing that the New Literature should grow out of the New Journalism, embracing "full-blooded realism".

"In abandoning social realism, novelists also abandoned certain vital matters of technique. As a result, by 1969 it was obvious that . . . magazine writers - the very lumpen proles themselves! - had also gained a technical edge on novelists. It was marvellous," Wolfe wrote.

Wolfe's literary enemies, the feisty novelist insists, are being left behind by his march on realism. "All three have seen the writing on the wall," he said, "and it reads: A Man in Full."

It is bitter dispute, spattered with the bile of old men with one eye on their rivals and the other on posterity. With the exception of Irving, all of them are in the late evening of their lives and can see the end coming. They are clearly in a rush, anxious to land a few last blows before the question of greatness is taken out of their hands for good.